It sounds like you're getting axial loads in beams due to gravity design with semi rigid turned on?
If there is, it shouldn't be much axial load at all.
I think you need to post some screen shots?...or ideally the EDB file?
Semi rigidity of diaphragm is a feature for lateral analysis only...
The trusses run down the entire length of building (into the page of your sketch).
In-plane diaphragm shear transfer through the diagonals.
The associated T/C resolved in the big beams.
think of a long braced frame elevation but tipped over on it's side...
there's details like the slab on left side of beam is very thick with real reinforcing... it steps down to the very shallow topping with poo poo mesh.
But the new strengthening bits are in green.
Green-
the load transfer originates from the bracing elements above the basement -> into the conc big beam line as a collector -> unloads to PFC channels which are epoxied to heck to said all conc collector beamline (all the bays are trimmed with PFCs in this zone) -> gussets from field...
Yes, i looked at diaphragm compatibility. The steel truss diaphragm strengthening indeed has to be the biggest tube you can get just to see the loads. I had to assume the 75mm topping was ineffective (eg a small inplane stiffness modifier) in order for the truss to participate as a diaphragm...
Thanks for the public announcement!
Hmm... i just a quick keyword search for pESA method being the way to load up diaphragms. I wish the updated 1170.5 would draw a straight line between diaphragm design actions and an equation. It doesn't do that. I get there's commentary, but it's just that...
Green
- it is indeed a regularly building.
-transfer forces are at worst on podium level, where the bracing lines for the apartments above do not extend below.
I think there's nuance here which is hard to convey in text (I dont really want to do broadcast sketches on this one).
But yes, there's enough shear friction from the starters in the topping to get load into the concrete beam grillage. Once the load is in a beam line (collector line) , I can...
Correction on my part - FRP calcs out with with pretty intense grillage of it but it would require evacuating the tenants above because it's a topside application.
I didn't do the truss method for diaphragm analysis, rather just semi rigid plate analysis within ETABS. The connections do take a...
Green
The 75mm topping slab has starters down to grillage of cast in place concrete beams (something like a 5.5-6m grid of them). I am inserting a steel truss diaphragm between said grillage with channel steel all around epoxied into said precast. The steel braces are connected via gusset plate...
Thanks Green,
I am interested in the in-plane diaphragm shear capacity of a transfer diaphragm above a basement. There's apartment mass uptop that wants to have it's shear forces transferred to the basement shearwalls below which are offset from the bracing system of said apartments.
The...
Hello fellow nerds,
I am exploring the idea of stitching together precast floor panels so I can unilise the entire depth of the floor (75topping+75unispan).
Is this a hair brained idea?
The top of unispan is indeed roughened so I believe it will act with the topping (just not at the abutting...
I've got a glass barrier for a hillside home in NZ, and in a an extremely high wind area, and the building faces downhill.
Since it's right on top of a wall I figure it's like a parapet so then NZS1170.2 section B.2.1 applies, right?
As for the site, design wind pressures = 1.95KPAxCshp
Cshp =...
I lean on the orange/pink(?) Timber Design book for now... so does the new Timber Material Design code take into effect immediately? Or do we have to wait for it to be referenced officially in B1/VM1. I ask because I imagine I need to spreadsheet up soon *eye roll*.
Greenalleycat-
The cladding panels have those steel angle bearing cleats welded to the PFC edge beam in that detail. Under in-plane inertial forces they they are all stitch plated (welds) together to minimize overturning and essentially the whole cladding line is in shear via the same welded...
Greenalleycat -
Definitely something site welded to a panel embed. But at the UC beam it will need a "pivot" connection to let the panel drift in-plane. Interestingly enough this concept is drawn up in a PCI connections manual! So at least we're not crazy here. But in USA they would not have...
Greenalleycat - these 120 panels are cladding only on the boundary line. There is a braced frame line beyond (like, where that 'torsion beam' is). The torsion beam is kicked back from the bottom flange (it's halftone in the snapshot). there are no vertical bars tying the cladding panels because...
